Josef roujjal



UNITED STATES UKUDD mzr Lumen PATENT OFFICE.

ELEOTRlO-ARO-LAM P CARBON.

srnemcsrron forming part of mm" new In scenes, dated Kay s, 1806.

To all whom it may concern.-

Be it known that I, JOSE? ROUBAL, a sub- 'ject of-the Emperor of.Austria-Hnngary, residing at Prague, Bohemia, Austria llun gary, 5- have invented certain new and useful Improvements inthe Manufacture of- Electric- Arc-Lamp carbons, of which the following is a specification, It is well known that the voltaic electric- :e light arc,inpassing from one carbon pointto the other, carries along with it carbon particles, some of which are unconsumed'an'd are scattered. This and the oxidation ofthe incandescent carbon points prevent tlieen s5 tire and full utilization of the carbonmand cause the tivecarbon to be pointed in the shape a cone, resnltingin an unsteady or flickering light. If, however, carbons are used which are not readily oxidised on the surse face, then the positive carbon point will itssums it round and almost cylindrical sha and the src will remain at the center an a steady ht will beobtsined.

The ob ect of my invention, therefore, is to :5 prepare the carbons in such a manner that. they will not readily oxidise on the surface. For this purpose! treat the carbon with a silicate. Silicic acid would be referable excepting that it does not exist soluble form. I therefore employ ssfiieatc, referablyone of thesilicatesof the alkslles, waterglaes.) fi'hccsrbonssresosked insmixture' or boric acid, substantially of equal parts of pnrsesrbon sndssiliest'e ggreferably a silicate of an alkali) and are en dried-rapidly. The silicatecombines in- 5 timately with the surface of the carbon and .the latter 'is thns incrusted Carbons for weaker currents should be soaked in solutions of boric acid.- The incrusting can be produced by applying the mixture by means of 4 a brush or by mung other suitable ways besides seeking, and t e silicate may be thinned as may be necessary.-

IIaving thus described my invention, what I clsimes new, and desire to secure by Letters Patent, is-

1. The process of treating electric-arc-light carbons, to prevent the oxidation on the sur-- face while burning and thereby lengthen the burning-time of the carbon, consisting ineostingand incrusting the carbon with a mixture of pure carbon and s silieate( erably silicate of an alkali or borie aci substantially as herein set orth. v

8. An electric-'arc-light carbon the surface "of which is incrnsted with a mixture of m carbon and a silicate (preferably water-g as set forth.

3 In testimony thstl elsimthe foregoing as my invention -I have signed my name in pres- 6e ence of two subscribing witnesses.

Hm! seasonal, Joan Von-rut. 

